The Games Workshop standard is 4' x 4' or 4'x6'; compared to the FFG 3' x 3'

Making a solid plastic board for the Death Star/Space Station scenario, is not difficult or too costly, it's that people will want the Trench Run, that's when the cost comes it. I think NOT making the board is less about the 3' x 3' x 1" plastic (whether one piece or two interlocking pieces), it's the next logical step in the requests.

Having said that, 4 of 9"x3' plates, the Trench is 6" to 7" wide and a little higher. If Trench = T and Plate = P then options are:

PTPPP, PPTPP, PPPTP

If the plates are interlocking, say board thickness about 1.5" thick and uses a solid connector to keep them together, then a few books ought to do it to keep the height difference.

OK, I'm sold on the idea.

FFG now you have to build it and take my money!